兩步
1.修改/etc/hostsname 爲你喜歡的名字 如 www.centos7.com
執行
hostnamectl set-hostname www.centos7.com
2 修改/etc/hosts,在最後添加上
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 wwww.centos7.com
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6